The present invention relates to a method of double injection molding and to a machine therefor, in which both single injection molding and double injection molding can be performed by the same machine.
One known two-color injection molding machine includes two injection units by which two molten synthetic resins are injected sequentially into dies tightened on each other by a single clamping unit and having a single gate.
To manufacture separately two molded products from different material or having two different colors, the products are molded by two molding machines.
Since the two-color injection molding machine does not include a unit for moving the two injection units transversely in the direction of the width of the bed of the machine, the machine can be used only for the dies having the corresponding gate position, but cannot used for other dies which are positioned differently. For that reason, the machine has a limited range of utility, thus increasing the cost of the equipment.
Where two molded products, having different colors or being made of different materials, are manufactured separately by two molding machines, there is a problem in that the cost of control of the number of the manufactured products and the cost of the equipment are high.